Abstract: A technique for modulating light by an optically addressed, electric charge accumulating spatial light modulator achieves substantially monotonic gray scale response. Embodiments digitally modulate the voltage across a photoreceptive material included in the spatial light modulator. The digital modulation scheme entails illuminating the photoreceptor with a series of light pulses propagating from an LCoS, in which the durations of the light pulses and their positions in time combine to produce binary-weighted equivalent rms voltages on the photoreceptor. The light pulses originate from a light-emitting diode or other switchable light source, and the timing of the light pulses is controlled such that they are emitted only when the associated LCoS is in a stable state. Emitting light pulses while the LCoS is in a stable state avoids non-monotonic behavior.

Abstract: An optically addressed, photoconductive spatial light modulator (SLM) operates in a transmissive mode and is capable of modulating a wide spectrum of visible light. There is no pixel structure or native pixel resolution in the SLM. The SLM has no photodiodes and does not rectify. A light projection system (100) in which one or more SLMs (128, 130, 132) are placed includes a write (image definition) UV light path (102) and a read (illumination) visible light path (104) to form a color image projection display. The write UV light propagates from an image display pattern source (120) and either sequentially or continuously writes image patterns on the photoconductive SLMs. The read visible light propagates through the SLM and is modulated by an electro-optical material, the optical properties of which change in response to the image structure carried by the write light. The result is a high efficiency display system that delivers high resolution color images through a projection lens (190) onto a display screen.

Abstract: A brake monitoring system for use on a motor vehicle includes a sensor connected to each brake actuator shaft on the motor vehicle for monitoring the position and travel of the brake actuator shaft and for generating and transmitting a brake condition signal; a data processor carried in an axle box associated with each axle and connected to sensors associated with brakes for the axle for receiving, interpreting, storing, and upon request, transmitting the brake condition signal, wherein each data processor includes an auto-address mechanism to identify its position on the vehicle; and a master station, wherein said master station includes a display for identifying a particular vehicle brake, a quantitative indication of the travel on the brake actuator shaft associated with the particular brake, and wherein said visual indicating devices include plural indicia which are indicative of said safety condition of a particular brake.

Abstract: Image defects are compensated by determining correction values based on an array of predetermined correction values based on display measurements. A correction value for a selected pixel is obtained by horizontal and vertical interpolation using the predetermined correction values. The computed correction values correspond to gain or offset corrections that are applied to input image values by multiplication or addition, respectively. Interpolation is based on predetermined correction values associated with a zone or subzones of a zone, or on an rate of change of an interpolation increment per row or per column.

Abstract: Display systems include display drivers that receive digital video data and retain digital pixel values corresponding to a row of pixels of a display panel. The retained digital pixel values are digitally compared with a digital count produced by a digital counter and at a transition time determined by the comparison of the digital pixel value and the digital count, a data ramp signal is applied to the pixel. The data ramp signal is configured to be time varying so that the transition time at which the data ramp signal is applied to the pixel can be used to establish a pixel voltage corresponding to a desired image value. In an example, digital pixel values corresponding to a first row of pixels are processed so that the data ramp signal is applied to each pixel of the first row at transition times determined by the digital image values associated with each pixel.

Abstract: Improved color ink-jet printing is accomplished by an ink-jet nozzle array configuration (32, 110) which has an odd number of nozzles (34) that are uniformly spaced apart by two line widths (2 V) such that naturally interlaced printing is accomplished when a print head (54) employing the nozzle array configuration is moved in uniformly stepped intervals. A color ink-jet print head employing the array configuration further employs multiple horizontally spaced apart instances (30) of the array in which each array ejects a particular color of ink, and the nozzles of each array are aligned in the direction of scanning to eject ink toward a common band of lines.

Abstract: A multi-orifice ink jet print head array (32) includes multiple drive circuits that drive respective PZTs (16) to cause ink drops to be ejected from respective orifices (28). Each drive circuit includes a voltage divider (36) having a resistor R.sub.S. The ink drop ejection velocity is controlled by selecting an appropriate value of R.sub.S for each voltage divider, thereby compensating for imperfections in manufacturing of the print head array. The value of a particular R.sub.S is selected by temporarily connecting the corresponding voltage divider (36A), in which the value of R.sub.S is R.sub.I, to assessment circuit (56). The assessment circuit includes a potentiometer (66) with resistance value R.sub.POT. Ink drops are ejected at a rapid periodic rate as a camera (102) records the position of the ink drops with respect to a graticule (94) at the time a strobe (100) flashes. The value of R.sub.POT is adjusted until the ink drops are on the graticule as viewed on a monitor (108), at which time R.sub.POT =R.

Abstract: The present invention (50) corrects duty-cycle errors generated by imperfections in encoder scales and encoder detectors. A preferred embodiment of the invention operates by detecting successive transparent-to-opaque transitions of the encoder scale (20), calculating the distance between the transitions, dividing that distance by two, and generating a synthetic encoder pluse that is timed to represent a position 50 percent of the distance between the transparent-to-opaque transitions.

Abstract: A print head, formed with spaced linear subheads of jet nozzles, prints all of the lines or image element rows on a print medium such as a sheet of paper by scanning along the face of the sheet. The head is advanced between scans by an equivalent number of lines generally equal to the number of nozzles in the head, whereby all print lines are addressed only once. Apparatus for printing includes the use of pointers in registers to keep track of head structure and location on a print medium for calculating print addresses. A partial page memory is used which wraps around to the beginning from the end. An edge sequence control logic circuit modifies the print data so that nozzles not over the image area do not print. A positive printer carriage position encoder uses an index marker located in the middle of a strip of incremental markers. Sensing of the index marker resets an up/down counter with a value that gives a positive value for all count conditions.

Abstract: Print heads are formed with spaced subheads having nozzles such that all of the lines or pixel rows on a print medium such as a sheet of paper are printed by scanning of the print head along the face of the sheet. The head structures include three subheads, each having nozzles for printing one or more adjacent lines with the subheads being spaced the same number of lines apart as the number of lines each prints; and three subheads spaced the equivalent of seven lines apart, each subhead having three nozzles spaced at the equivalent of alternate lines. The heads are advanced between scans by an equivalent number of lines generally equal to the number of nozzles in the head, whereby all print lines are addressed only once. Apparatus for printing includes the use of pointers in registers to keep track of head structure and location on a print medium for calculating print addresses. A partial page memory is used which wraps around to the beginning from the end.

Abstract: Print heads are formed with spaced subheads having nozzles such that all of the lines or pixel rows on a print medium such as a sheet of paper are printed by scanning of the print head along the face of the sheet. The head structures include three subheads, each having nozzles for printing one or more adjacent lines with the subheads being spaced the same number of lines apart as the number of lines each prints; and three subheads spaced the equivalent of seven lines apart, each subhead having three nozzles spaced at the equivalent of alternate lines. The heads are advanced between scans by an equivalent number of lines generally equal to the number of nozzles in the head, whereby all print lines are addressed only once. Apparatus for printing includes the use of pointers in registers to keep track of head structure and location on a print medium for calculating print addresses. A partial page memory is used which wraps around to the beginning from the end.

Abstract: A light beam positioning system (10) has the capability of generating accurately positioned beam paths at programmed velocities between any two positions on a target surface (18). The beam positions correspond to beam position and velocity command data processed by a system control computer (22). The invention employs an error correction processor (52) that receives X and Y position coordinate signals (X and Y signals) produced by a conventional position data generator and develops compensated X and Y position coordinate signals (X.sub.c and Y.sub.c signals) for delivery to a light beam positioner (12). The X.sub.c and Y.sub.c signals are derived from a calibration map of an addressable field representing the positions to which the light beam can be commanded on the target surface. The X.sub.c and Y.sub.c signals represent polynominal functions of the X and Y signals and offset beam position errors resulting from the light-directing properties of the system optical components (26, 28, 30).